Comparators are used in many applications, including analog-to-digital converters, data transmission components (e.g. infrared transceivers), and switching power regulators.
Some comparators are provided with “hysteresis”, which can be defined as a comparator's varying response to rising and falling input signal edges. In many cases, hysteresis is used to prevent a comparator's output from oscillating as a result of noise in the vicinity of a signal's edges.